Only one small problem : '.config/openbox/lxde-rc.xml' doesn't do not its job. The superkey in combination with a letter shows a small rectangle in the upper right corner of the screen with that letter inside instead of starting a program. (eg : "W-f" for starting PCManFM)

Had a look : the windows key (superkey) under 'xev' gives : keycode 133 (keysym 0xffeb, Super_L) which is OK, I think.

Thank you for reacton.
You are right about 'W-f'. But the problem remains :

IIn the original '.config/openbox/lxde-rc.xml' :
"W-e" = PCManFM
"W-r" = lxpanelctl run
But nothing happens : only a small rectangle in the upper right corner of the screen with that letter('e' / 'r') inside instead of starting PCManFM or running lxpanelctl.